Plate finishing machine



Aug.v 27, 1940. c. J. sTRANG PLATE FINISHING MACHINE Filed Jan. l5, 19382 Sheets-Sheet l Aug. 27, 1940.

C. J. STRANG PLATE FINISHING MACHINE Filed Jan. 15, 1938 2 Sheets-Sheet2 ZUM Patented Aug. 27, 1940 PATENT OFFlCE PLATE FIN ISHING MACHINECortland J. Strang, Mount Vernon, N. Y., assignor to Wood NewspaperMachinery Corporation, New York, N. Y., a, corporation of VirginiaApplication January 15, 1938, Serial No. 185,097

3 Claims.

This invention relates to an improved means for finishing moreaccurately and With less distortion the inner surface of a caststereotype plate.

The principal objects of the invention are to provide a shaving knife ofthe .ordinary type and means for driving said shaving knife in acircular path, concentric with the outer surface of the stereotypeplate, in combination with a rotary cutter following said knife forproviding (the nish shaving of the plate andrendering it more accurate;to provide separate and independent means for rotating the cutter at theproper speed during the driving of the cutter bodily in a circular path;to arrange said shaving knife and rotary cutter in such a relativemanner that the knife precedes the rotary cutter, removing part of theexcess metal on the inner surface of the plate and also pressing theplate into more intimate contact with the inner surface of the shavingarch and the rotary cutter will follow it With the plate in accurateposition, taking oi the rest of the surplus metal and thus producing amore accurately finished inner concave surface of the stereotype platethan has been the case heretofore, and to provide means for adjustingradially the position of the straight bladed advance cutter so as toaccurately finish the inner surface of the plate.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 isa longitudinal sectional elevation of a plate finishing machineconstructed in accordance with this invention;

Fig, 2 is a side view of the same;

Fig. 3 is a sectional vieW on the line 3-3 of Fig. 1 showing inelevation the end of the machine, and

Fig. 4 is a sectional view on the line 4-4 of Fig. 2.

In order to divide up the shaving yof the concave side of a curvedstereotype printing plate an advance shaving blade of the ordinary typeis used to take 01T only part of the metal removed by the correspondingblade in previous constructions and also to force the plate up into afinished arch. [Said blade is followed in this machine by a planetarycutter which rotates always on its own axis and simultaneously rotatesbodily on the axis of the arch, The second cutter removes the rest ofthe surplus material on the inside of the plate but .only after theinside of the plate has been firmly and accurately fixed in the arch.

This results in a much better shaving of the plate because the finishingcut is made after the plate has been set back into its nal position inthe arch and after it is practically impossible for the plate to move orshift during this shaving :5 operation.

In order to accomplish these purposes, the cast stereotype plate I to befinished is held tightly in the shaving arch 2 by means of a pluralityof y rollers 3 actuated by a lifting mechanism 4. The 10 opposite edgesof the plate I rest on the tops of these rollers and the liftingmechanism which is shown merely holds them up in the arch on both sides,as has been done heretofore. The shaving knife bar 5 arrangedlongitudinally is rigidly 15 mounted in bearings and revolves about thelongitudinal center of the concaved inner surface of the shaving arch 2.The shaving knife bar 5 is driven by an electric motor B, or othermeans, through a belt 1, worm 8 and worm gear 9, in 20 the presentinstance, in the direction indicated by the arrow in Fig. 3. The shavingknife bar 5 carries the substantially radial shaving knife II) and arotary cutter H. The shaving knife I is adjustabiy mounted so as to moveradially to control the radius of the rst cut on the inside surface ofthe printing plate. The adjustment of the shaving knife throughadjusting screws 2| and nuts 23 controls the amount of excess metalremoved from the inside of the stereotype plate by this cutter, ofcourse. The action .of the shaving knife, is such that part of theexcess metal on the inner surface of the stereotype plate is removed. Atthe same time the action of the shaving knife pushes the plate intocloser proximity with the inner surface of the shaving arch.

The rotary or planetary cutter II is supported at each end byanti-friction bearings I2 mounted in eccentric bushings I3. Saideccentric bushings are free to rotate within spaces provided in theshaving knife bar 5. An electric motor 24 at the entrance end of themachine drives the rotary cutter II in a planetary path by means of agear I mounted on the extreme end of the rotary cutter and gears IB andI'l, the rotary cutter drive shaft I8 and gears I9 and 2D associatedtherewith. The rotary cutter drive shaft I8 is supported byanti-friction bearings 22 Within the shaving knife bar 5. It is solocated that the longitudinal center line of said shaft coincides withthe longitudinal center line of said shaving knife bar. By means ofadjusting screws I 4 located on opposite sides `of the eccentricbushings I3, said bushings can be radially adjusted within the spacesprovided for them Within the shaving knife bar 5. This controls thedepth of the finishing cut taken on the inside surface of the plate I.The cutting action of the rotary cutter is inherently easy as there islittle thrust on the plate. The excess metal remaining on the insidesurface of the stereotype plate I after the shaving knife l0 has removedpart of the metal is accurately removed without distorting the plate.This is possible because the knife I0 is also forcing the stereotypeplate into closer conformity to the concave finished surface .of theshaving arch.

An accuracy of finish on the inside surface of the plate is obtained bythis invention which is greater than the accuracy of finish in theinside surface of a similar plate obtained by shaving with a singleknife because the first action of this invention is to force thestereotype plate into close conformity with the shaving arch withoutdistorting or deforming said plate. The removing of the other part ofthe excess metal is a comparatively easy process not only on account ofthe comparative thickness of the excess metal remored but also onaccount of the rotary cutting Cir-.ration This inner surface isfinished, and leaves a proper backing for the plate so that the typesurface thereon will fit this surface and not be likely to be injured atany point. There is only sufficient cf the excess metal on the insidesurface of the plate removed by said shaving knife to secure the desiredconformity of the plate to the arch s0 that the plate is not deformed ordistorted by the cutting action. The desired plate shaped with the typesurface to conform with the inner concave surface of the shaving arch isobtained without the usual distortion by a shaving knife which takes offthe entire surplus metal and thus has a much deeper cut than is the casehere.

Should the shaving knife press up, non-printing surfaces, however, theplate will have suffi cient spring to react to proper position by thetime the rotary cutter comes along, and thus a truly finished plate isobtained.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details of construction herein described,otherwise than as set forth in the claims, but what I claim is:

l. In a finishing machine for stereotype printing plates, thecombination of a rotary longitudinal shaving knife bar, a radial knifesubstantially fixed thereon for cutting surplus material from the insideof a stereotype plate in the preliminary cutting operation and forcingand firmly seating the plate in the arch, and a rotary cutter rotatingon an axis parallel with the axis of said bar and rotating bodily aboutthe axis of the bar arranged to follow the knife for finishing the sameinside surface of the plate after it is forced back to its seat andshaved by the knife.

2. In a stereotype plate finishing machine, the combination of an archhaving a concave finished inner surface for receiving the type surfaceof a stereotype plate, a longitudinal shaving knife bar within said archhaving a substantially radial knife for performing the preliminarycutting operation and seating the plate in the arch firmly, a rotarycutter following the knife for finishing the same interior surfacehaving an axis parallel to the axis of the shaving knife bar, means foradjusting the shaving knife radially toward and from the arch, means forrotating the shaving knife bar on its axis, and means for rotating therotary cutter on its own axis.

3. In a stereotype plate finishing machine, the combination of an archhaving a concave finished inner surface for receiving the type surfaceof a stereotype plate, a longitudinal shaving knife bar within said archhaving a substantially radial knife for performing the first cuttingoperation and seating the plate in the arch firmly, a rotary cutterbehind the radial knife for finishing the interior partly finishedsurface having an axis parallel to the axis of the shaving knife bar,means for adjusting the rotary cutter toward and from the arch, meansfor rotating the shaving knife bar on its axis, and means connected withthe last named means for rotating the rotary cutter positively on itsown axis while it is moving about the axis of the shaving knife bar.

CORTLAND J. STRANG.

